A typical optical cable splice closure has a number of ports for receiving fiber optic cables. After being passed into a port, a fiber optic cable is mechanically secured to the closure, has its outer plastic and metallic sheath removed, and has its core tube, which encase the optical fibers, split and routed to one or more splice trays inside protective tubes. Within the splice trays, the optical fibers are removed from their respective protective tubes and are spliced to other fibers. The optical splice closure usually can accommodate a number of splice trays, with each splice tray holding a number of splices. For protection of the optical fibers which are exposed within the closure, the closure generally has a number of components for sealing it from the outside environment.
In a widely used prior art lightguide closure, which will be discussed more fully hereinafter, sealing is achieved by means of a grommet disposed between the flanges of upper and lower halves of a two part closure shell, with the two halves being clamped together. The closure thus formed has openings at each end through which the cables are introduced into the interior of the closure. Each end of the grommet has inner and outer bored blocks adapted to receive and embrace the cables which are anchored in cable grips mounted adjacent to the cable seals just inside the closure. The placing of each cable within its respective bore is facilitated by means of a longitudinal slit within the block over each bore so that the bore can be opened up sufficiently to receive the cable or grommet plug and, when released, tightly embrace them. In those cases where a bore does not receive a cable, it must be independently sealed by means of, for example, a solid grommet plug. In addition, where a cable is to be passed straight through the closure without splicing, it is sometimes necessary to have slits formed in the cable embracing grommet to facilitate locating the cable within the inner and outer bored blocks of the grommet.
The splice closures of the prior art are generally designed to accommodate a range of cable diameters, however, they require that the installer or splicer carry a corresponding range of grommets, each having different size bores, both split and unsplit. The grommets are, themselves, somewhat expensive to manufacture because of their generally unique configuration. It has been the accepted practice to produce them by casting them in an open mold process out of polyurethane, which is a relatively expensive and time consuming process.